Slowbalt2000

iTrader: (1)

Thats a mighty big feed! You got a restricter in there?

patooyee

What size would people normally use there? That's a good point though, that seems like a huge pressure leak ...

Slowbalt2000

iTrader: (1)

I use a -4an with a restrictor fitting. Most people use -3 or -4.

Slowbalt2000

iTrader: (1)

Just for reference i use a -10 drain.

patooyee

Link to restrictor fitting?

Slowbalt2000

iTrader: (1)

I got it off ebay forever ago. Just search for oil restrictor and your thread size. Idk if the k04 and gt28 use the same threads.

patooyee

I'm looking at them now ... they appear to just be fittings with smaller than normal holes in them. None of them easily fit the plumbing I have going on right now though. I think I may do some more research and look into making a new adapter fitting for the block with a calibrated, undersized hole instead of the full-bore one that I put in the current fitting. This would allow me to keep the existing hard lines that I have made. Another thing though, with a restricted supply line, why the -10 return? Seems like even a -6 should easily be able to drain whatever the small orifice fitting will supply?

Thanks again for all the help. This is why I joined this site. This is my first small engine and first turbo engine so all this information is helping me a lot. I think most can tell by now that I'm OK at fabrication , design, engineering, etc., but just out of my element with forced induction and 4-cylinders.

Slowbalt2000

iTrader: (1)

You still have to fill that entire feed line with oil though, just seems too big imo but ill let someone else give theirs as well. The restrictor goes on the turbo side though, not the block. -10 is just what most people use because you dont want it getting backed up and cook the oil, im sure you can get away with smaller, just the kit that i bought is all.

I can definitely tell this isnt your first rodeo, haha just helping where i can. 4cyl turbo cars are my forte but im working on building a 402 BBC from the ground up so thats new to me.

patooyee

So the restrictor would go in the turbo oil inlet? ... my idea with making a smaller-bore fitting would work there as well. The oil pump should be more than capable of filling that small line. The remote filter lines will be bigger than it is and most people don't worry about those.

Slowbalt2000

iTrader: (1)

I guess so, just make sure to figure that all into your oil capacity.

Slowbalt2000

iTrader: (1)

Yes, to your first question

Sharkey

iTrader: (1)

be careful with restrictors. many turbos now have a calibrated orifice (aka restrictor) built into the turbo, other turbos simply dont require them. if you run one with a turbo that doesnt require it itll take the bearings out of the turbo in short order. i cant say ive ever worked with a turbo that required a restrictor.

typically a -4 or 1/4" line is run for oil feed. keep in mind that a larger oil feed line wont actually feed more oil or make it so you require a restrictor. keep in mind that the adapter fitting you screwed into the block (or the banjo bolt) only has roughly a 1/4" inside diameter. -10 or 5/8, or larger is needed for return, this is because the return relies on gravity. if you dont have a large enough return the oil with back up into the turbo and cause the seals to leak, and the end result will be a smoking turbo.

patooyee

After reading about turbo oil requirements and understanding the issue better now I do think I will go back and re-do that drain line to -10. It makes sense to me now why that port on the turbo is the only one that uses a flange. A fitting would take up some of the bore reducing overall drain capacity. This sucks because I will have to pull the oil pan again, grind the fitting off, and weld a new one on. Better now than in the buggy after a smoked turbo though. I've got an email into BNR asking about the inlet port / restrictor requirements.

patooyee

I spent a lot of time yesterday mocking up my intake. Its is difficult fitting it as close to the block between the fuel rail and remote oil filter fittings where I want it. This is what I tentatively have planned for now. As already mentioned, the D-shaped plenum material I bought was way too big so I cut it down the center and weld it back together with this design.











The length of the runners is not finalized yet but, as you can see in the last transparent image, getting to a few of the intake manifold bolts will be difficult with the plenum so close to the head. Once I decide for sure that this is the design I want to go with I will french some round tubing in from the sides to allow a socket and extension to go through the intake and access the few bolts that are masked by the intake. I'll wait for input from ya'll to finalize anything ...

BTW, the odly-shaped intake manifold flange is just a trace of a random dimensional drawing from GM that I found on the internet. While the bolt hole placement is correct, the outer path of the actual flange I got from Zero Level is nothing close to that. The flange thickness in the drawing is matched to the ZL flange which, for modeling purposes, is all that matters. The faded gray circle in some of the views is a 70mm TB bore. My TB is actually only 67mm but I figured I would give myself a little fudge-space during fabrication. This intake points the TB backwards towards the transmission, which the way it will be mounted in the chassis, points forwards.

Slowbalt2000

iTrader: (1)

I dont take airflow class until next semester but i just dont like how small the plenum gets for that last runner. I guess it doesnt matter as much for boosted applications though.

patooyee

That's what I kind of thought at first as well. But then I looked at the intake manifold on my tow rig, which is about 450 hp, 850 ft/lbs, over double the displacement, and nothing on it is any bigger. It uses almost the same size turbo, too. I guess the boost is always ramming air in there so it's just not a big deal?

patooyee

Another idea I had was to abandon the runners / plenum design and build something more like this:



Nothing is going to hug the block better than that ...

Slowbalt2000

iTrader: (1)

Hmm. Im unsure which way that would shift the powerband but im assuming up.

patooyee

Here's the best info I've found so far, not saying anything for its validity, but if you believe it, it would seem that the tapered shape would actually HELP airflow across the 4 ports:

Intake manifold design

YelloEye

iTrader: (3)

I think that manifold setup is designed more for vehicles without a bypass or blowoff valve like diesels. The turbo is always spinning at a decent amount and that pressure doesn't get released except by being introduced into the combustion chamber. So there's plenty of pressurized air available basically all the time.

patooyee

Does everyone generally agree that this is the correct plumbing diagram? In my case my BOV would recirc back to in front of the turbo. (TB would be between MAF and engine.)

Slowbalt2000

iTrader: (1)

If you have the maf after the bov then you dont need a recirc

patooyee

My main intent of wanting to recirc was to reduce the hissing sound and also to keep dirt and debris out of the BOV since this is a 100% off-road application. (I kind of want to make this thing a sleeper. You know, roll up on a hill where all the heavy V8 guys are and then blow their socks off when I walk up it. )

Slowbalt2000

iTrader: (1)

Are you going to have the motor covered? Lol

patooyee

There will be body panels to protect me from fires but no, the motor will be exposed to the elements. Such is standard for tube buggies. If you look at the examples of other buggies like this that I posted pics of in the beginning of the thread you can see what I am talking about.